The present invention relates generally to mechanical devices and methods used in laparoscopic surgical procedures to remove organs and excised tissue from internal body cavities.
It will be appreciated by those skilled in the art that the use of bags or pouches to remove organs and large tissue specimen during laparoscopic surgical procedures is well known. As described, for example, in U.S. Pat. No. 5,147,371 a pouch is introduced into the abdominal cavity for retrieving gallstones and tissue. The bag is opened and closed using a wire loop as a drawstring. In U.S. Pat. No. 5,192,284 an expandable bag is inserted into the abdominal cavity through a trocar cannula. The bag described in the '284 patent is made of a memory material that is rigid enough to support itself. The bag expands and remains open when it is inserted into the abdominal cavity through the cannula. U.S. Pat. No. 5,480,404 describes a pouch for extracting tissue that is opened and closed by a ratchet mechanism. U.S. Pat. No. 5,341,815 employs shape memory effect metal to open the bag upon insertion through a trocar. U.S. Pat. Nos. 5,681,324 and 5,971,995 describe similar bags and pouches.
The pouches described in these patents are useful in containing any bile or gallstones that might otherwise spill into the abdominal cavity during extraction of a torn gallbladder. These types of devices, however, suffer from at least three problems. Since such devices are closed on the distal end, air inside the enclosure tends to balloon the pouches or bags during the extraction process thereby increasing the size or not allowing a full collapse of a bag as it is removed from the wound. Additionally, when the tissue is larger than the wound size, it is forced to the bottom of the bag as the radial force of the wound acts on the tissue during extraction. This also increases the size to which the wound must be dilated for removal of the tissue. Tapering the bags toward the distal end helps somewhat to lessen this effect, but the result is not optimal and does not fully address the problem of air trapped in the bag. Finally, the work required to remove a gall bladder is equal to the extraction force times the distance over which the force is required to act plus any heat generated by friction. For example the work required to remove a bagged gallbladder with a 30 mm diameter stone is the same as the work required to extract the same gall bladder that is contained in a rigid shallow cone with a maximum diameter of 30 mm (neglecting friction differences). The peak force for removal is much higher, however, for the bagged gallbladder since the force is required to act over a much smaller distance. Since it is desirable to minimize the forces required to extract a gallbladder owing to material and human limitations, the gallbladder should be, by way of example only, contained in a rigid shallow cone rather than a flexible bag.
Since the goal of laparoscopic surgery is to become less invasive by using smaller entry wounds, the prior art is of limited value for removing large specimens through, for example, 5 mm wounds. When the user pulls on the bag in an attempt to remove it through a small trocar entry wound, the specimen is forced to the bottom of the bag by the radial forces exerted by the abdominal tissue or by the forces exerted on the bag from the cannula, thus creating a large lump that is often incapable of passing through the wound without tearing the bag. The use of this type of extraction bag in these cases often requires de-bulking of the specimen so that the bagged specimen pieces are of such a size that the bag can be extracted through the trocar entry wound, typically 10–12 mm. This is a time consuming process that is not always successful since, for example, large stones may be inside a gallbladder and the process usually necessitates the pathologic examination of the tissue specimen. As an alternative to de-bulking, the wound size may be increased with a scalpel to allow the extraction. This approach, however, lessons the advantage of the laparoscopic surgery. Additionally, these types of extraction bags add undue complexity to the procedure since they require the use of two ports, one for the bag and a second for a grasper to retrieve the tissue and put it into the bag.
U.S. Pat. Nos. 5,190,561 and 5,370,647 to Graber disclose several embodiments of laparoscopic extraction devices that allow a grasper to be inserted into the center of an extractor device so that tissue can be more easily manipulated into the inside of the extractor. In each of the embodiments the extractor is introduced into the abdominal cavity through a specially designed trocar cannula equipped with setscrews to lock the extractor to the trocar cannula. Upon exiting the distal end of the cannula, the distal end of the extractor expands, much like an umbrella. A grasper is then introduced into the abdominal cavity through a lumen in the extractor. The specimen is grasped and pulled into the expanded open distal end of the extractor, a cone-shaped device. The grasper is then locked to the cannula using the setscrews. The proximal end of the extractor is equipped with a handle, which is used to pull the extractor and the tissue through the cannula. As the handle is pulled upward “ . . . the enveloping means collapses around the tissue and returns to its pre-deployment.” The enveloping means of Graber '647 is relied on to compress the tissue to a size that allows it to be drawn into a hollow tubular shroud 610 (see FIG. 13 of Graber '647). Thus, the device is not optimally designed to deal with a tissue specimen that will not compress to a point so that it can be drawn into the shroud.
The extractor of Graber '647 also has several other disadvantages. The Graber '647 device is ill-suited for use with standard trocars because it utilizes setscrews, which are not generally available on trocars in current use, to lock it to the trocar. The Graber '647 device also utilizes an expensive locking mechanism to lock the grasper to the extractor. In addition, most abdominal laparoscopic procedures are performed with the abdominal cavity insufflated with carbon dioxide. The lumen in the extractor of Graber '647 has no provision for sealing and thus when the extractor is placed through the seal of the trocar, the abdomen will loose its carbon dioxide pressure through the lumen of the extractor.
The Graber '647 device is removed from the body cavity by an exertion force on the handle of the device. This unduly places rotational and shear forces on the extractor-grasper lever lock and the extractor-trocar setscrews because of the vigorous rotational manipulation required to remove it from the abdominal wall.
One of the extractor covers disclosed in the Graber '647 patent is made from “a sturdy waterproof, stain resistant fabric such as treated sailcloth or duck cloth.” These materials are thick, bulky, and generally not suited for extractors for use with less invasive trocar cannula such as 5 mm and smaller devices. In particular, such covers require multiple folds in order for the extractor to pass through a small-bore cannula. FIG. 24 of the Graber '647 patent discloses a thin “baggie,” however, it requires thick leaves 608 and a plunger rod 606 to compress the tissue. The combination and thickness of these features is unduly complicating and makes the Graber device ill-suited for small cannulas.
The embodiment disclosed in FIG. 12 of the Graber '647 patent teaches the use of a flexible, waterproof web material with an opening mouth so that tissue can enter the rib portion 510. While this embodiment partially solves the spillage problem it unduly complicates manipulating the tissue inside the extractor and is overly complex in that the extractor cover and the spillage compartment are made of two separate pieces which must be joined by sewing, heat treating, or welding.
Graber also discloses a multi-leaf rigid cover that is pinned to a hollow elongated shank. The leaves are rolled into a generally cylindrical shape inside the shank in an un-deployed state and expanded into a generally conical shape in a deployed state. An extraction dilation device having a single leaf is desirable owing to its simplicity. Graber does not teach a method or mechanism for attaching a single leaf to the shank since fixedly pinning a single-leaf sheet to the shank results in buckling of the cone when attempting to roll it into a generally cylindrical shape for insertion within a tube.
Laparoscopic removal of the gallbladder has, heretofore, entailed the use of four entry cannula, typically two of which are 10 to 12 mm in diameter and two of which are 5 mm in diameter. The two 5 mm ports are used to accept instruments such as scissors, graspers, electro-surgery probes, and suction/irrigation devices. The 10 to 12 mm ports are employed to allow the use of instruments such as a 10 mm endoscope attached to a camera for viewing the surgical field or a clip applier for ligating vessels and ducts, and to permit the removal of a gallbladder following its excision.
In an effort to make the procedure less invasive, 5 mm clip appliers have been developed, such as described by Shipp et al. in U.S. Pat. No. 5,858,018, the disclosure of which is incorporated by reference herein. The 5 mm clip applier allows the conversion of one of the two 10 to 12 mm ports to a third 5 mm port. The remaining 10 to 12 mm port prior to this invention has been required to accept 10 mm endoscopes and to permit the removal of the gallbladder, usually through the umbilicus port site. New bright 5 mm endoscopes coupled with more sensitive cameras have been developed that are quite acceptable substitutes for the prior art camera systems. These developments leave gallbladder removal through a 5 mm or smaller port as the last obstacle to the full conversion of the process to four much less invasive 5 mm ports. The conversion from two 10 to 12 mm trocars and two 5 mm trocars to four 5 mm trocars lowers the total entry wound area by 50 percent, which greatly reduces bleeding and post surgery incisional herniation at the wound sites.
What is needed then is a simple, inexpensive device and an easy to use method for rapid removal of tissue, such as a gallbladder, from a wound site that has an opening size that is smaller than the size of the specimen and does not require substantial secondary operations such as grinding the specimen into smaller pieces or significantly enlarging the wound size. Also needed is a simple, rigid single-leaf dilator extractor that is attached to a hollow shank such that the leaf may easily be rolled into a shape exhibiting a minimal diameter for insertion into a small trocar cannula, for example, 5 mm. Preferably, the deployed dilator extractor is sufficiently rigid so as to provide a smooth, shallow angled cone shape so that the force required to remove the tissue is minimized. Preferably, the dilator extractor is self-deployable to a sufficient base diameter upon exiting the cannula, even after prolonged storage in a rolled-up or un-deployed state.